It is well known to prepare epoxy compounds by reacting epihalohydrin with an active hydrogen-containing compound and subsequently dehydrohalogenating the chlorohydrin intermediate product with a basic acting compound such as an alkali or alkaline earth metal hydroxide or carbonate. Since epichlorohydrin is prepared in three steps from propylene (the very basic starting material) this entire process for the preparation of glycidyl ether (or other glycidyl derivative) based epoxy resins involves four or five steps depending upon whether or not steps four and five are conducted simultaneously or separately. The five-step reaction is as follows:
1) propylene+chlorine - - -&gt; allyl chloride
2) allyl chloride+water+chlorine - - -&gt; dichloropropanol
3) dichloropropanol+NaOH - - -&gt; epichlorohydrin
4) epichlorohydrin+active hydrogen-containing compound such as a bisphenol - - -&gt; chlorohydrin intermediate
5) chlorohydrin intermediate+basic acting compound - - -&gt; glycidyl ether epoxy resin
In the four-step reaction, steps four and five are conducted essentially simultaneously.
The most widely used current processes for the preparation of epichlorohydrin also produce a significant amount of chlorinated by-product such as 2-chloropropene, 2-chloropropane, allyl chloride, 1,2-dichloropropane, 3,3-dichloropropene, 2,3-dichloropropene, 1,3-dichloropropene, 1,3,3-trichloropropene, 1,2,3-trichloropropane, bis(dichloropropyl)ethers, 2,3-dichloro-1-propanol, 1,3-dichloro-2-propanol. These by-products must be sold into a useful market or disposed of by environmentally friendly methods. Moreover, certain of the by-products are difficult to separate from the epihalohydrin. When the epihalohydrin is used to make epoxy resin, the epoxy resin becomes contaminated with undesirable bound and hydrolyzable halides resulting from reaction by-products and from incompletely reacted epihalohydrin.
What is needed is a process to make similar epoxy resins or other glycidyl compounds which process has one or more of the following advantages: fewer process steps, fewer halogenated by-products, and/or lower levels of halogenated contaminants, by-products, in the resulting resin or compound or simultaneously having an epoxide equivalent weight less than about 200 and an amount of total organic halide of less than about 200 ppm excluding any halogen atoms attached to an aromatic ring to which the group containing the vicinal epoxide group is attached.